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Frequently Asked Questions – Ultrapac™ 2000

Q. Why Does the Dryer Make a “Humming” or Vibrating Noise?

A. The UP2000 is designed to operate under an infinitely variable set of operating pressures, flow rates, and wide range of temperatures. In very rare applications, a certain unique combination of flow and temperature may cause the regeneration membrane valve to vibrate at an audible frequency that produces a hum-like tone (pressure regulators will sometimes do this as well for the exact same reasons). There are three possible remedies for this:

  1. Adjust the upstream pressure of the system so that there will be a slightly different flow rate through the regeneration circuit.
  2. If the system cannot tolerate a different pressure, change the regeneration throttle element to the next larger size. Doing this will cause enough of a change in air flow that the conditions should no longer be conducive to causing the membrane oscillation.
  3. Change the durometer of the internal valve membrane elastomer. Installing a softer material for the valve will cause the material to no longer respond to the conditions that caused the vibration. 
Q. How Can I Adapt the Dryer to Operate at Peak Efficiency Under Non-Standard Operating Conditions?

A. The UP2000 dryers are factory set to produce a -40 PDP for the rated flows under fully saturated conditions at 100psig/95°F. However, the dryer is still useable within the ranges of 60psi-225psi and 40-125°F when we change the regeneration airflow throttle orifice size.

  1. When operating pressure is >100psig, the throttle size must be reduced. This is due to the fact that the amount of water vapor reduces with increasing pressure, while at the same time the flow rate through a given orifice will increase. The opposite case is true for operating pressures <100psig.

  2. When operating temperature is >95˚F, the adsorption characteristics of the desiccant are reduced. This requires an increase in regeneration air demand and hence a larger throttle size. The opposite case is true for air of cooler temperatures.
Figure 1
Q. How Do I Put the Dryer into Stand-By Mode?

A. If the dryer is not needed, it can be put into “stand-by mode” by making a connection between terminals 1 and ground on the Hirschmann-type connector (see Figure 1). This connection is usually made by a relay, but can also be accomplished by other means such as a manual switch or a process integrated relay. In this mode, the dryer will continue to allow air flow but will not consume any power or use air for regeneration.

Figure 2
Q. How Can I Output an Alarm or Service Signal?

A. As depicted in Figure 2, a relay control (max. 45VDC / 200mA) can be operated directly between terminals 3-ground in the event the dryer indicates an alarm or service condition. During operation the relay is normally closed and open during an alarm and/or service event. If a diode is not already integrated with the relay, make sure to connect one in parallel to protect the electronics of the dryer. Refer to Figure 2 for dryer-side connection to the Hirschmann connector. 

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Figure 3
Q. What Is the Installation and Startup Procedure for the UP2000?

1. Installation

The dryer shall be installed on a sturdy, level surface. The weight of the dryer should be transferred to the supporting structure by the feet rather than the connecting pipework. When fastening the inlet and outlet piping, a suitable wrench should be used to counteract the tightening force as to not allow this torque to be transmitted to the dryer. A good method is to use an adjustable wrench to hold the aluminum block that contains the threaded female connections while tightening the connections. Please reference Figure 3. 

2. Startup 
It is recommended that the dryer be installed with a three-valve bypass arrangement so that compressed air can be distributed even while the dryer is being serviced. An example of this arrangement is shown below:

  1. Using the figure above, check that valves A and B in the by-pass line (optional) have been closed and that the electrical controller has been switched off.

  2. Slowly build up the pressure in the dryer by slowly opening valve A.

  3. Apply power to the electrical controller.

  4. The controller starts with the pressure build-up phase in both adsorbers. Finally, the regeneration phase begins in one of the adsorbers and the adsorption phase in the other adsorber.

    Note that moisture from the ambient air can get into the desiccant as a result of transport or storage of the dryer. For that reason, the dryer must be regenerated for at least 3 hours before the initial startup and before the butterfly valve B is opened to the compressed air network.

  5. The dryer is integrated into the compressed air network by slowly opening valve B.

  6. Close valve C if this had been opened during startup.

    Please note that during operation, the dryer will make a sound like air is leaking out of it. This is normal. This will continue to happen until the unit is ready to switch towers and then there will be a blast of air discharging from the unit. It will then go back to the sound of air leaking out as this cycle will continue while the unit is in operation.
Figure 4

3. Clearing the Desiccant Service Light (standard version only)
After desiccant cartridge replacement, the controller must be reset. Before performing the procedure, be sure the unit does not have power.

As shown in Figure 4, the reset switch is located in the control block. Remove the two screws along with the cover to expose the reset switch. Flip the reset switch to the other position and re-install the cover.

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